This invention relates to new improved hydrophilic crosslinked polyurethane foams and to a method for their preparation. More particularly, the present invention relates to hydrophilic foams prepared from a capped polyoxyethylene polyol reactant having a defined average reaction functionality greater than two which is then admixed with large amounts of an aqueous reactant.
Numerous attempts have been made in the prior art to produce hydrophilic polyurethane foams. Typically, these attempts have been based on (1) inclusion of a separate hydrophilic additive into a hydrophobic polyisocyanate either during or after foaming; or (2) use of reactants such as polyoxyethylene polyol and a polyisocyanate with low, i.e. near stoichiometric amounts of water, and a catalyst; and (3) foams based on non-catalytic reactions using linear polyoxyethylene diols, diisocyanate and varying amounts of water.